Heterojunction Bipolar Transistor (HBT) transistors are used in many applications, such as signal generators in car RAdio Detection And Ranging (RADAR) or similar microwave applications, requiring high switching frequencies. To improve the figure of merit maximum switching frequency (fmax), it is important to reduce the amount of parasitic resistances and capacitances as well as keeping the base width of the transistor at the minimum value possible. At the same time, manufacturing costs should be kept low.